1 /*-
2 * Copyright (c) 2012 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Mindaugas Rasiukevicius.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 /*
31 * npfctl(8) extension loading interface.
32 */
33
34 #include <sys/cdefs.h>
35 __RCSID("$NetBSD: npf_extmod.c,v 1.5 2018/09/29 14:41:36 rmind Exp $");
36
37 #include <stdlib.h>
38 #include <inttypes.h>
39 #include <string.h>
40 #include <err.h>
41 #include <dlfcn.h>
42
43 #include "npfctl.h"
44
45 struct npf_extmod {
46 char * name;
47 npfext_initfunc_t init;
48 npfext_consfunc_t cons;
49 npfext_paramfunc_t param;
50 struct npf_extmod * next;
51 };
52
53 static npf_extmod_t * npf_extmod_list;
54
55 static void *
npf_extmod_sym(void * handle,const char * name,const char * func)56 npf_extmod_sym(void *handle, const char *name, const char *func)
57 {
58 char buf[64];
59 void *sym;
60
61 snprintf(buf, sizeof(buf), "npfext_%s_%s", name, func);
62 sym = dlsym(handle, buf);
63 if (sym == NULL) {
64 errx(EXIT_FAILURE, "dlsym: %s", dlerror());
65 }
66 return sym;
67 }
68
69 static npf_extmod_t *
npf_extmod_load(const char * name)70 npf_extmod_load(const char *name)
71 {
72 npf_extmod_t *ext;
73 void *handle;
74 char extlib[PATH_MAX];
75
76 snprintf(extlib, sizeof(extlib), "/lib/npf/ext_%s.so", name);
77 handle = dlopen(extlib, RTLD_LAZY | RTLD_LOCAL);
78 if (handle == NULL) {
79 errx(EXIT_FAILURE, "dlopen: %s", dlerror());
80 }
81
82 ext = ecalloc(1, sizeof(npf_extmod_t));
83 ext->name = estrdup(name);
84 ext->init = npf_extmod_sym(handle, name, "init");
85 ext->cons = npf_extmod_sym(handle, name, "construct");
86 ext->param = npf_extmod_sym(handle, name, "param");
87
88 /* Initialise the module. */
89 if (ext->init() != 0) {
90 free(ext);
91 return NULL;
92 }
93
94 ext->next = npf_extmod_list;
95 npf_extmod_list = ext;
96 return ext;
97 }
98
99 npf_extmod_t *
npf_extmod_get(const char * name,nl_ext_t ** extcall)100 npf_extmod_get(const char *name, nl_ext_t **extcall)
101 {
102 npf_extmod_t *extmod = npf_extmod_list;
103
104 while (extmod) {
105 if ((strcmp(extmod->name, name) == 0) &&
106 (*extcall = extmod->cons(name)) != NULL) {
107 return extmod;
108 }
109 extmod = extmod->next;
110 }
111
112 extmod = npf_extmod_load(name);
113 if (extmod && (*extcall = extmod->cons(name)) != NULL) {
114 return extmod;
115 }
116
117 return NULL;
118 }
119
120 int
npf_extmod_param(npf_extmod_t * extmod,nl_ext_t * ext,const char * param,const char * val)121 npf_extmod_param(npf_extmod_t *extmod, nl_ext_t *ext,
122 const char *param, const char *val)
123 {
124 return extmod->param(ext, param, val);
125 }
126